L12 strengthened amorphous aluminum alloys

ABSTRACT

An improved amorphous aluminum alloy having high strength, ductility, corrosion resistance and fracture toughness is disclosed. The alloy has an amorphous phase and a coherent L1 2  phase. The alloy has nickel, cerium, at least one of scandium, erbium, thulium, ytterbium, and lutetium; and at least one of gadolinium, yttrium, zirconium, titanium, hafnium, niobium and iron. The volume fraction of the amorphous phase ranges from about 50 percent to about 95 percent and the volume fraction of the coherent L1 2  phase ranges from about 5 percent to about 50 percent.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to the following co-pending applicationsthat are filed on even date herewith and are assigned to the sameassignee: L1₂ ALUMINUM ALLOYS WITH BIMODAL AND TRIMODAL DISTRIBUTION,Ser. No. ______, Attorney Docket No. PA0006933U-U73.12-325KL; DISPERSIONSTRENGTHENED L1₂ ALUMINUM ALLOYS, Ser. No. ______, Attorney Docket No.PA0006932U-U73.12-326KL; HEAT TREATABLE L1₂ ALUMINUM ALLOYS, Ser. No.______, Attorney Docket No. PA0006931U-U73.12-327KL; HIGH STRENGTH L1₂ALUMINUM ALLOYS, Ser. No. ______, Attorney Docket No.PA0006929U-U73.12-329KL; HIGH STRENGTH L1₂ ALUMINUM ALLOYS, Ser. No.______, Attorney Docket No. PA0006928U-U73.12-330KL; HEAT TREATABLE L1₂ALUMINUM ALLOYS, Ser. No. ______, Attorney Docket No.PA0006927U-U73.12-331KL; HIGH STRENGTH L1₂ ALUMINUM ALLOYS, Ser. No.______, Attorney Docket No. PA0006926U-U73.12-332KL; HIGH STRENGTHALUMINUM ALLOYS WITH L1₂ PRECIPITATES, Ser. No. ______, Attorney DocketNo. PA0006942U-U73.12-334KL; and HIGH STRENGTH L1₂ ALUMINUM ALLOYS, Ser.No. ______, Attorney Docket No. PA0006923U-U73.12-335YKL.

BACKGROUND

The present invention relates generally to aluminum alloys and morespecifically to L1₂ phase dispersion strengthened aluminum alloys havingceramic reinforcement particles.

The combination of high strength, ductility, and fracture toughness, aswell as low density, make aluminum alloys natural candidates foraerospace and space applications. However, their use is typicallylimited to temperatures below about 300° F. (149° C.) since mostaluminum alloys start to lose strength in that temperature range as aresult of coarsening of strengthening precipitates.

The development of aluminum alloys with improved elevated temperaturemechanical properties is a continuing process. Some attempts haveincluded aluminum-iron and aluminum-chromium based alloys such asAl—Fe—Ce, Al—Fe—V—Si, Al—Fe—Ce—W, and Al—Cr—Zr—Mn that containincoherent dispersoids. These alloys, however, also lose strength atelevated temperatures due to particle coarsening. In addition, thesealloys exhibit ductility and fracture toughness values lower than othercommercially available aluminum alloys.

Other attempts have included the development of mechanically alloyedAl—Mg and Al—Ti alloys containing ceramic dispersoids. These alloysexhibit improved high temperature strength due to the particledispersion, but the ductility and fracture toughness are not improved.

U.S. Pat. No. 6,248,453 discloses aluminum alloys strengthened bydispersed Al₃X L1₂ intermetallic phases where X is selected from thegroup consisting of Sc, Er, Lu, Yb, Tm, and U. The Al₃X particles arecoherent with the aluminum alloy matrix and are resistant to coarseningat elevated temperatures. The improved mechanical properties of thedisclosed dispersion strengthened L1₂ aluminum alloys are stable up to572° F. (300° C.). U.S. Patent Application Publication No. 2006/0269437A1 discloses an aluminum alloy that contains scandium and otherelements.

Amorphous alloys have received interest in recent years becausematerials with an amorphous structure are usually very strong andcorrosion resistant in comparison with crystalline structures having thesame composition. However, amorphous aluminum alloys have been found tohave lower ductility and fracture toughness than the crystalline form.Aluminum based amorphous alloys with high strength and low density aredesirable because of their lower density and their applicability in theaerospace and space industries. Amorphous aluminum alloys would also beuseful in armor applications where lightweight materials are desired.

SUMMARY

The present invention is an improved amorphous aluminum alloy having acrystalline L1₂ aluminum alloy phase dispersed in an amorphous aluminumalloy matrix. The L1₂ phase results in improved ductility and fracturetoughness while maintaining the strength and corrosion resistance of theamorphous phase. The desired volume fraction of the amorphous phase isfrom about 50 percent to about 95 percent, more preferably about 60percent to about 90 percent, and even more preferably about 70 percentto about 80 percent.

The aluminum alloy of this invention is formed into the amorphous phaseand a fine, coherent L1₂ phase by use of the rapid solidificationprocess.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an aluminum nickel phase diagram.

FIG. 2 is an aluminum cerium phase diagram.

FIG. 3 is an aluminum scandium phase diagram.

FIG. 4 is an aluminum erbium phase diagram.

FIG. 5 is an aluminum thulium phase diagram.

FIG. 6 is an aluminum ytterbium phase diagram.

FIG. 7 is an aluminum lutetium phase diagram.

DETAILED DESCRIPTION

The alloys of this invention comprises an amorphous matrix of aluminum,nickel and cerium strengthened by having dispersed therein a fine,coherent L1₂ phase based on Al₃X where X is least one first elementselected from scandium, erbium, thulium, ytterbium, lutetium, and atleast one second element selected from iron, gadolinium, yttrium,zirconium, titanium, hafnium, and niobium.

The aluminum nickel phase diagram is shown in FIG. 1. The aluminumnickel binary system is a simple eutectic at 5.7 weight percent nickeland 1183.8° F. (639.9° C.). There is little solubility of nickel inaluminum. However, the solubility can be extended significantly byutilizing rapid solidification processes. The equilibrium phase in thealuminum nickel eutectic system is intermetallic Al₃Ni.

The aluminum cerium phase diagram is shown in FIG. 2. The aluminumcerium binary system is a simple eutectic at 18 weight percent ceriumand 1184° F. (640° C.). There is little or no solubility of cerium inaluminum. However the solubility can be extended significantly byutilizing rapid solidification processes. Metastable Al₃Ce can form inrapidly cooled hypereutectic aluminum cerium alloys. The equilibriumphase in eutectic alloys is Al₁₁Ce₃ Cerium helps in forming an amorphousstructure in aluminum in the presence of nickel due to deep eutectics.

Scandium forms Al₃Sc dispersoids that are fine and coherent with thealuminum matrix. Lattice parameters of aluminum and Al₃Sc are very close(0.405 nm and 0.410 nm respectively), indicating that there is minimalor no driving force for causing growth of the Al₃Sc dispersoids. Thislow interfacial energy makes the Al₃Sc dispersoids thermally stable andresistant to coarsening up to temperatures as high as about 842° F.(450° C.). In the alloys of this invention these Al₃Sc dispersoids aremade stronger and more resistant to coarsening at elevated temperaturesby adding suitable alloying elements such as gadolinium, yttrium,zirconium, titanium, hafnium, niobium, iron or combinations thereof,that enter Al₃Sc in solution.

Erbium forms Al₃Er dispersoids in the aluminum matrix that are fine andcoherent with the aluminum matrix. The lattice parameters of aluminumand Al₃Er are close (0.405 nm and 0.417 nm respectively), indicatingthere is minimal driving force for causing growth of the Al₃Erdispersoids. This low interfacial energy makes the Al₃Er dispersoidsthermally stable and resistant to coarsening up to temperatures as highas about 842° F. (450° C.). In the alloys of this invention, these Al₃Erdispersoids are made stronger and more resistant to coarsening atelevated temperatures by adding suitable alloying elements such asgadolinium, yttrium, zirconium, titanium, hafnium, niobium, iron orcombinations thereof that enter Al₃Er in solution.

Thulium forms metastable Al₃Tm dispersoids in the aluminum matrix thatare fine and coherent with the aluminum matrix. The lattice parametersof aluminum and Al₃Tm are close (0.405 nm and 0.420 nm respectively),indicating there is minimal driving force for causing growth of theAl₃Tm dispersoids. This low interfacial energy makes the Al₃Tmdispersoids thermally stable and resistant to coarsening up totemperatures as high as about 842° F. (450° C.). In the alloys of thisinvention these Al₃Tm dispersoids are made stronger and more resistantto coarsening at elevated temperatures by adding suitable alloyingelements such as gadolinium, yttrium, zirconium, titanium, hafnium,niobium, iron or combinations thereof that enter Al₃Tm in solution.

Ytterbium forms Al₃Yb dispersoids in the aluminum matrix that are fineand coherent with the aluminum matrix. The lattice parameters of Al andAl₃Yb are close (0.405 nm and 0.420 nm respectively), indicating thereis minimal driving force for causing growth of the Al₃Yb dispersoids.This low interfacial energy makes the Al₃Yb dispersoids thermally stableand resistant to coarsening up to temperatures as high as about 842° F.(450° C.). In the alloys of this invention, these Al₃Yb dispersoids aremade stronger and more resistant to coarsening at elevated temperaturesby adding suitable alloying elements such as gadolinium, yttrium,zirconium, titanium, hafnium, niobium, iron or combinations thereof thatenter Al₃Yb in solution.

Lutetium forms Al₃Lu dispersoids in the aluminum matrix that are fineand coherent with the aluminum matrix. The lattice parameters of Al andAl₃Lu are close (0.405 nm and 0.419 nm respectively), indicating thereis minimal driving force for causing growth of the Al₃Lu dispersoids.This low interfacial energy makes the Al₃Lu dispersoids thermally stableand resistant to coarsening up to temperatures as high as about 842° F.(450° C.). In the alloys of this invention, these Al₃Lu dispersoids aremade stronger and more resistant to coarsening at elevated temperaturesby adding suitable alloying elements such as gadolinium, yttrium,zirconium, titanium, hafnium, niobium, iron or mixtures thereof thatenter Al₃Lu in solution.

Gadolinium forms metastable Al₃Gd dispersoids in the aluminum matrixthat are stable up to temperatures as high as about 842° F. (450° C.)due to their low diffusivity in aluminum. The Al₃Gd dispersoids have anL1₂ structure in the metastable condition and a D0₁₉ structure in theequilibrium condition. Despite its large atomic size, gadolinium hasfairly high solubility in the Al₃X intermetallic dispersoids (where X isscandium, erbium, thulium, ytterbium or lutetium). Gadolinium cansubstitute for the X atoms in Al₃X intermetallic, thereby forming anordered L1₂ phase which results in improved thermal and structuralstability.

Yttrium forms metastable Al₃Y dispersoids in the aluminum matrix thathave an L1₂ structure in the metastable condition and a D0₁₉ structurein the equilibrium condition. The metastable Al₃Y dispersoids have a lowdiffusion coefficient which makes them thermally stable and highlyresistant to coarsening. Yttrium has a high solubility in the Al₃Xintermetallic dispersoids allowing large amounts of yttrium tosubstitute for X in the Al₃X L1₂ dispersoids which results in improvedthermal and structural stability.

Zirconium forms Al₃Zr dispersoids in the aluminum matrix that have anL1₂ structure in the metastable condition and D0₂₃ structure in theequilibrium condition. The metastable Al₃Zr dispersoids have a lowdiffusion coefficient which makes them thermally stable and highlyresistant to coarsening. Zirconium has a high solubility in the Al₃Xdispersoids allowing large amounts of zirconium to substitute for X inthe Al₃X dispersoids, which results in improved thermal and structuralstability.

Titanium forms Al₃Ti dispersoids in the aluminum matrix that have an L1₂structure in the metastable condition and D0₂₂ structure in theequilibrium condition. The metastable Al₃Ti despersoids have a lowdiffusion coefficient which makes them thermally stable and highlyresistant to coarsening. Titanium has a high solubility in the Al₃Xdispersoids allowing large amounts of titanium to substitute for X inthe Al₃X dispersoids, which result in improved thermal and structuralstability.

Hafnium forms metastable Al₃Hf dispersoids in the aluminum matrix thathave an L1₂ structure in the metastable condition and a D0₂₃ structurein the equilibrium condition. The Al₃Hf dispersoids have a low diffusioncoefficient, which makes them thermally stable and highly resistant tocoarsening. Hafnium has a high solubility in the Al₃X dispersoidsallowing large amounts of hafnium to substitute for scandium, erbium,thulium, ytterbium, and lutetium in the above mentioned Al₃Xdispersoides, which results in stronger and more thermally stabledispersoids.

Niobium forms metastable Al₃Nb dispersoids in the aluminum matrix thathave an L1₂ structure in the metastable condition and a D0₂₂ structurein the equilibrium condition. Niobium has a lower solubility in the Al₃Xdispersoids than hafnium or yttrium, allowing relatively lower amountsof niobium than hafnium or yttrium to substitute for X in the Al₃Xdispersoids. Nonetheless, niobium can be very effective in slowing downthe coarsening kinetics of the Al₃X dispersoids because the Al₃Nbdispersoids are thermally stable. The substitution of niobium for X inthe above mentioned Al₃X dispersoids results in stronger and morethermally stable dispersoids.

Iron forms Al₆Fe dispersoids in the aluminum matrix in the metastablecondition, and forms Al₃Fe dispersoids in the equilibrium condition.Iron has a little solubility in aluminum matrix in the equilibriumcondition which can be extended significantly by a rapid solidificationprocess. Iron can be very effective in slowing down the coarseningkinetics because the Al₆Fe dispersoids are thermally stable due to itsvery low diffusion coefficient in aluminum. Iron provides solid solutionand dispersion strengthening in aluminum.

The amount of nickel present in the matrix of this invention may varyfrom about 4 to about 25 weight percent, more preferably from about 6 toabout 20 weight percent, and even more preferably from about 8 to about15 weight percent.

The amount of cerium present in the matrix of this invention may varyfrom about 2 to about 25 weight percent, more preferably from about 4 toabout 20 weight percent, and even more preferably from about 6 to about15 weight percent.

The amount of scandium present in the alloys of this invention, if any,may vary from about 0.1 to about 4 weight percent, more preferably fromabout 0.1 to about 3 weight percent, and even more preferably from about0.2 to about 2.5 weight percent. The Al—Sc phase diagram shown in FIG. 3indicates a eutectic reaction at about 0.5 weight percent scandium atabout 1219° F. (659° C.) resulting in a solid solution of scandium andaluminum and Al₃Sc dispersoids. Aluminum alloys with less than 0.5weight percent scandium can be quenched from the melt to retain scandiumin solid solution that may precipitate as dispersed L1₂ intermetallicAl₃Sc following an aging treatment. Alloys with scandium in excess ofthe eutectic composition (hypereutectic alloys) can only retain scandiumin solid solution by rapid solidification processing (RSP) where coolingrates are in excess of about 10³° C./second. Alloys with scandium inexcess of the eutectic composition cooled normally will have amicrostructure consisting of relatively large Al₃Sc dispersoids in afinally divided aluminum-Al₃Sc eutectic phase matrix.

The amount of erbium present in the alloys of this invention, if any,may vary from about 0.1 to about 20 weight percent, more preferably fromabout 0.3 to about 15 weight percent, and even more preferably fromabout 0.5 to about 10 weight percent. The Al—Er phase diagram shown inFIG. 4 indicates a eutectic reaction at about 6 weight percent erbium atabout 1211° F. (655° C.). Aluminum alloys with less than about 6 weightpercent erbium can be quenched from the melt to retain erbium in solidsolutions that may precipitate as dispersed L1₂ intermetallic Al₃Erfollowing an aging treatment. Alloys with erbium in excess of theeutectic composition can only retain erbium in solid solution by rapidsolidification processing (RSP) where cooling rates are in excess ofabout 10³° C./second. Alloys with erbium in excess of the eutecticcomposition cooled normally will have a microstructure consisting ofrelatively large Al₃Er dispersoids in a finely divided aluminum-Al₃Ereutectic phase matrix.

The amount of thulium present in the alloys of this invention, if any,may vary from about 0.1 to about 15 weight percent, more preferably fromabout 0.2 to about 10 weight percent, and even more preferably fromabout 0.4 to about 6 weight percent. The Al—Tm phase diagram shown inFIG. 5 indicates a eutectic reaction at about 10 weight percent thuliumat about 1193° F. (645° C.). Thulium forms metastable Al₃Tm dispersoidsin the aluminum matrix that have an L1₂ structure in the equilibriumcondition. The Al₃Tm dispersoids have a low diffusion coefficient whichmakes them thermally stable and highly resistant to coarsening. Aluminumalloys with less than 10 weight percent thulium can be quenched from themelt to retain thulium in solid solution that may precipitate asdispersed metastable L1₂ intermetallic Al₃Tm following an agingtreatment. Alloys with thulium in excess of the eutectic composition canonly retain Tm in solid solution by rapid solidification processing(RSP) where cooling rates are in excess of about 10³° C./second.

The amount of ytterbium present in the alloys of this invention, if any,may vary from about 0.1 to about 25 weight percent, more preferably fromabout 0.3 to about 20 weight percent, and even more preferably fromabout 0.4 to about 10 weight percent. The Al—Yb phase diagram shown inFIG. 6 indicates a eutectic reaction at about 21 weight percentytterbium at about 1157° F. (625° C.). Aluminum alloys with less thanabout 21 weight percent ytterbium can be quenched from the melt toretain ytterbium in solid solution that may precipitate as dispersed L1₂intermetallic Al₃Yb following an aging treatment. Alloys with ytterbiumin excess of the eutectic composition can only retain ytterbium in solidsolution by rapid solidification processing (RSP) where cooling ratesare in excess of about 10³° C./second.

The amount of lutetium present in the alloys of this invention, if any,may vary from about 0.1 to about 25 weight percent, more preferably fromabout 0.3 to about 20 weight percent, and even more preferably fromabout 0.4 to about 10 weight percent. The Al—Lu phase diagram shown inFIG. 7 indicates a eutectic reaction at about 11.7 weight percent Lu atabout 1202° F. (650° C.). Aluminum alloys with less than about 11.7weight percent lutetium can be quenched from the melt to retain Lu insolid solution that may precipitate as dispersed L1₂ intermetallic Al₃Lufollowing an aging treatment. Alloys with Lu in excess of the eutecticcomposition can only retain Lu in solid solution by rapid solidificationprocessing (RSP) where cooling rates are in excess of about 10³°C./second.

The amount of gadolinium present in the alloys of this invention, ifany, may vary from about 2 to about 30 weight percent, more preferablyfrom about 4 to about 25 weight percent, and even more preferably fromabout 6 to about 20 weight percent.

The amount of yttrium present in the alloys of this invention, if any,may vary from about 2 to about 30 weight percent, more preferably fromabout 4 to about 25 weight percent, and even more preferably from about6 to about 20 weight percent.

The amount of zirconium present in the alloys of this invention, if any,may vary from about 0.5 to about 5 weight percent, more preferably fromabout 1 to about 4 weight percent, and even more preferably from about 1to about 3 weight percent.

The amount of titanium present in the alloys of this invention, if any,may vary from about 0.5 to about 10 weight percent, more preferably fromabout 1 to about 8 weight percent, and even more preferably from about 1to about 4 weight percent.

The amount of hafnium present in the alloys of this invention, if any,may vary from about 0.5 to about 10 weight percent, more preferably fromabout 1 to about 8 weight percent, and even more preferably from about 1to about 4 weight percent.

The amount of niobium present in the alloys of this invention, if any,may vary from about 0.5 to about 5 weight percent, more preferably fromabout 1 to about 4 weight percent, and even more preferably from about 1to about 3 weight percent.

The amount of iron present in the matrix of this invention may vary fromabout 0.5 to about 15 weight percent, more preferably from about 1 toabout 10 weight percent, and even more preferably from about 2 to about8 weight percent.

Forming the amorphous structure of this invention enhances the strengthof the alloys, whereas ductility, fracture toughness and thermalstability are increased by the dispersed, fine, coherent L1₂ particlesin the microstructure.

Exemplary aluminum alloys of this invention include, but are not limitedto (in weight percent):

about Al-(4-25)Ni-(2-25)Ce-(0.1-4)Sc-(2-30)Gd;

about Al-(4-25)Ni-(2-25)Ce-(0.1-20)Er-(2-30)Gd;

about Al-(4-25)Ni-(2-25)Ce-(0.1-15)Tm)-(2-30)Gd;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Lu)-(2-30)Gd;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Yb-(2-30)Gd;

about Al-(4-25)Ni-(2-25)Ce-(0.1-4)Sc-(2-30)Y;

about Al-(4-25)Ni-(2-25)Ce-(0.1-20)Er-(2-30)Y;

about Al-(4-25)Ni-(2-25)Ce-(0.1-15)Tm)-(2-30)Y;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Lu)-(2-30)Y;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Yb-(2-30)Y;

about Al-(4-25)Ni-(2-25)Ce-(0.1-4)Sc-(0.5-5)Zr;

about Al-(4-25)Ni-(2-25)Ce-(0.1-20)Er-(0.5-5)Zr;

about Al-(4-25)Ni-(2-25)Ce-(0.1-15)Tm)-(0.5-5)Zr;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Lu)-(0.5-5)Zr;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Yb-(0.5-5)Zr;

about Al-(4-25)Ni-(2-25)Ce-(0.1-4)Sc-(0.5-10)Ti;

about Al-(4-25)Ni-(2-25)Ce-(0.1-20)Er-(0.5-10)Ti;

about Al-(4-25)Ni-(2-25)Ce-(0.1-15)Tm-(0.5-10)Ti;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Lu-(0.5-10)Ti;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Yb-(0.5-10)Ti;

about Al-(4-25)Ni-(2-25)Ce-(0.1-4)Sc-(0.5-10)Hf;

about Al-(4-25)Ni-(2-25)Ce-(0.1-20)Er-(0.5-10)Hf;

about Al-(4-25)Ni-(2-25)Ce-(0.1-15)Tm-(0.5-10)Hf;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Lu)-(0.5-10)Hf;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Yb-(0.5-10)Hf,

about Al-(4-25)Ni-(2-25)Ce-(0.1-4)Sc-(0.5-5)Nb;

about Al-(4-25)Ni-(2-25)Ce-(0.1-20)Er)-(0.5-5)Nb;

about Al-(4-25)Ni-(2-25)Ce-(0.1-15)Tm-(0.5-5)Nb;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Lu)-(0.5-5)Nb;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Yb-(0.5-5)Nb;

about Al-(4-25)Ni-(2-25)Ce-(0.1-4)Sc-(0.5-15)Fe;

about Al-(4-25)Ni-(2-25)Ce-(0.1-20)Er)-(0.5-15)Fe;

about Al-(4-25)Ni-(2-25)Ce-(0.1-15)Tm-(0.5-15)Fe;

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Lu)-(0.5-15)Fe; and

about Al-(4-25)Ni-(2-25)Ce-(0.1-25)Yb-(0.5-15)Fe.

In the inventive aluminum based alloys disclosed herein, scandium formsan equilibrium Al₃Sc intermetallic dispersoid that has an L1₂ structurethat is an ordered face centered cubic structure with the Sc atomslocated at the corners and aluminum atoms located on the cube faces ofthe unit cell.

In order to have the best properties for the alloys of this invention,it is desirable to limit the amount of other elements. Specific elementsthat should be reduced or eliminated include no more that about 0.1weight percent chromium, 0.1 weight percent manganese, 0.1 weightpercent vanadium and 0.1 weight percent cobalt. The total quantity ofadditional elements should not exceed about 1% by weight, including theabove listed impurities and other elements.

These aluminum alloys may be made by rapid solidification processing.The rapid solidification process should have a cooling rate greater thatabout 10³° C./second including but not limited to powder processing,atomization, melt spinning, splat quenching, spray deposition, coldspray, plasma spray, laser melting and deposition, ball milling andcryomilling.

More exemplary aluminum alloys of this invention include, but are notlimited to (in weight percent):

about Al-(6-20)Ni-(4-20)Ce-(0.1-3)Sc-(4-25)Gd;

about Al-(6-20)Ni-(4-20)Ce-(0.3-15)Er-(4-25)Gd;

about Al-(6-20)Ni-(4-20)Ce-(0.2-10)Tm)-(4-25)Gd;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Lu)-(4-25)Gd;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Yb-(4-25)Gd;

about Al-(6-20)Ni-(4-20)Ce-(0.1-3)Sc-(4-25)Y;

about Al-(6-20)Ni-(4-20)Ce-(0.3-15)Er-(4-25)Y;

about Al-(6-20)Ni-(4-20)Ce-(0.2-10)Tm)-(4-25)Y;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Lu)-(4-25)Y;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Yb-(4-25)Y;

about Al-(6-20)Ni-(4-20)Ce-(0.1-3)Sc-(1-4)Zr;

about Al-(6-20)Ni-(4-20)Ce-(0.3-15)Er-(1-4)Zr;

about Al-(6-20)Ni-(4-20)Ce-(0.2-10)Tm)-(1-4)Zr;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Lu)-(1-4)Zr;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Yb-(1-4)Zr;

about Al-(6-20)Ni-(4-20)Ce-(0.1-3)Sc-(1-8)Ti;

about Al-(6-20)Ni-(4-20)Ce-(0.3-15)Er-(1-8)Ti;

about Al-(6-20)Ni-(4-20)Ce-(0.2-10)Tm-(1-8)Ti;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Lu-(1-8)Ti;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Yb-(1-8)Ti;

about Al-(6-20)Ni-(4-20)Ce-(0.1-3)Sc-(1-8)Hf;

about Al-(6-20)Ni-(4-20)Ce-(0.3-15)Er-(1-8)Hf;

about Al-(6-20)Ni-(4-20)Ce-(0.2-10)Tm-(1-8)Hf;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Lu-(1-8)Hf;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Yb-(1-8)Hf;

about Al-(6-20)Ni-(4-20)Ce-(0.1-3)Sc-(1-3)Nb;

about Al-(6-20)Ni-(4-20)Ce-(0.3-15)Er-(1-3)Nb;

about Al-(6-20)Ni-(4-20)Ce-(0.2-10)Tm-(1-3)Nb;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Lu-(1-3)Nb;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Yb-(1-3)Nb;

about Al-(6-20)Ni-(4-20)Ce-(0.1-3)Sc-(1-10)Fe;

about Al-(6-20)Ni-(4-20)Ce-(0.3-15)Er)-(1-10)Fe;

about Al-(6-20)Ni-(4-20)Ce-(0.2-10)Tm-(1-10)Fe;

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Lu)-(1-10)Fe; and

about Al-(6-20)Ni-(4-20)Ce-(0.3-20)Yb-(1-10)Fe.

More preferred examples of similar alloys to these are alloys with about8 to about 15 weight percent nickel and about 6 to about 15 weightpercent cerium, and include, but are not limited to (in weight percent):

about Al-(8-15)Ni-(6-15)Ce-(0.2-2.5)Sc-(6-20)Gd;

about Al-(8-15)Ni-(6-15)Ce-(0.5-10)Er-(6-20)Gd;

about Al-(8-15)Ni-(6-15)Ce-(0.4-6)Tm-(6-20)Gd;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Lu-(6-20)Gd;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Yb-(6-20)Gd;

about Al-(8-15)Ni-(6-15)Ce-(0.2-2.5)Sc-(6-20)Y;

about Al-(8-15)Ni-(6-15)Ce-(0.5-10)Er-(6-20)Y;

about Al-(8-15)Ni-(6-15)Ce-(0.4-6)Tm-(6-20)Y;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Lu-(6-20)Y;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Yb-(6-20)Y;

about Al-(8-15)Ni-(6-15)Ce-(0.2-2.5)Sc-(1-3)Zr;

about Al-(8-15)Ni-(6-15)Ce-(0.5-10)Er-(1-3)Zr;

about Al-(8-15)Ni-(6-15)Ce-(0.4-6)Tm-(1-3)Zr;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Lu-(1-3)Zr;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Yb-(1-3)Zr;

about Al-(8-15)Ni-(6-15)Ce-(0.2-2.5)Sc-(1-4)Ti;

about Al-(8-15)Ni-(6-15)Ce-(0.5-10)Er-(1-4)Ti;

about Al-(8-15)Ni-(6-15)Ce-(0.4-6)Tm-(1-4)Ti;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Lu-(1-4)Ti;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Yb-(1-4)Ti;

about Al-(8-15)Ni-(6-15)Ce-(0.2-2.5)Sc-(1-4)Hf;

about Al-(8-15)Ni-(6-15)Ce-(0.5-10)Er-(1-4)Hf;

about Al-(8-15)Ni-(6-15)Ce-(0.4-6)Tm-(1-4)Hf;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Lu-(1-4)Hf;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Yb-(1-4)Hf;

about Al-(8-15)Ni-(6-15)Ce-(0.2-2.5)Sc-(1-3)Nb;

about Al-(8-15)Ni-(6-15)Ce-(0.5-10)Er)-(1-3)Nb;

about Al-(8-15)Ni-(6-15)Ce-(0.4-6)Tm-(1-3)Nb;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Lu)-(1-3)Nb;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Yb-(1-3)Nb;

about Al-(8-15)Ni-(6-15)Ce-(0.2-2.5)Sc-(2-8)Fe;

about Al-(8-15)Ni-(6-15)Ce-(0.5-10)Er)-(2-8)Fe;

about Al-(8-15)Ni-(6-15)Ce-(0.4-6)Tm-(2-8)Fe;

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Lu)-(2-8)Fe; and

about Al-(8-15)Ni-(6-15)Ce-(0.4-10)Yb-(2-8)Fe.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1. An aluminum alloy having high strength, ductility, corrosionresistance and fracture toughness, comprising: an amorphous phasealuminum alloy comprising about 4 to 25 weight percent of nickel andabout 2 to about 25 weight percent of cerium; a coherent L1₂ phasecomprising: about 4 to about 25 weight percent nickel and about 2 toabout 25 weight percent of cerium, at least one first element selectedfrom the group comprising: about 0.1 to about 4 weight percent scandium,about 0.1 to about 20 weight percent erbium, about 0.1 to about 15weight percent thulium, about 0.1 to about 25 weight percent ytterbium,and about 0.1 to about 25 weight percent lutetium; at least one secondelement selected from the group comprising: about 2 to about 30 weightpercent gadolinium, about 2 to about 30 weight percent yttrium, about0.5 to about 5 weight percent zirconium, about 0.5 to about 10 weightpercent titanium, about 0.5 to about 10 weight percent hafnium, about0.5 to about 5 weight percent niobium, and about 0.5 to about 15 weightpercent iron; and the balance substantially aluminum.
 2. The alloy ofclaim 1, wherein the volume fraction of the amorphous phase ranges fromabout 50 percent to about 95 percent and the volume fraction of thecoherent L1₂ phase ranges from about 5 percent to about 50 percent. 3.The alloy of claim 1, comprising no more than about 1 weight percenttotal impurities.
 4. The alloy of claim 1, comprising no more than about0.1 weight percent chromium, about 0.1 weight percent manganese, about0.1 weight percent vanadium, and about 0.1 weight percent cobalt.
 5. Thealloy of claim 1, where the alloy is formed by a rapid solidificationprocess.
 6. The aluminum alloy of claim 5, wherein the rapidsolidification process has a cooling rate greater that about 10³°C./second.
 7. The alloy of claim 6, wherein the rapid solidificationprocess comprises at least one of powder processing, atomization, meltspinning, splat quenching, spray deposition, cold spray, plasma spray,laser melting and deposition, ball milling and cryomilling.
 8. Analuminum alloy having high strength, ductility, corrosion resistance andfracture toughness, comprising: nickel; cerium; at least one firstelement selected from the group comprising: about 0.1 to about 4 weightpercent scandium, about 0.1 to about 20 weight percent erbium, about 0.1to about 15 weight percent thulium, about 0.1 to about 25 weight percentytterbium, and about 0.1 to about 25 weight percent lutetium; at leastone second element selected from the group comprising: gadolinium,yttrium, zirconium, titanium, hafnium, niobium and iron; and the balancesubstantially aluminum.
 9. The alloy of claim 8, wherein the alloycomprises: about 4 to about 25 weight percent nickel; about 2.0 to about25 weight percent cerium; at least one first element selected from thegroup comprising: about 0.1 to about 4 weight percent scandium, about0.1 to about 20 weight percent erbium, about 0.1 to about 15 weightpercent thulium, about 0.1 to about 25 weight percent ytterbium, andabout 0.1 to about 25 weight percent lutetium; and at least one secondelement selected from the group comprising about 2 to about 30 weightpercent gadolinium, about 2 to about 30 weight percent yttrium, about0.5 to about 5 weight percent zirconium, about 0.5 to about 10 weightpercent titanium, about 0.5 to about 10 weight percent hafnium, about0.5 to about 5 weight percent niobium, and 0.5 to about 15 weightpercent iron.
 10. The alloy of claim 8, wherein the volume fraction ofthe amorphous phase ranges from about 50 percent to about 95 percent andthe volume fraction of the coherent L1₂ phase ranges from about 5percent to about 50 percent.
 11. A method of forming an aluminum alloyhaving high strength, ductility and toughness, the method comprising:(a) forming an alloy powder comprising: about 4 to 25 weight percent ofnickel and about 2 to about 25 weight percent of cerium; at least onefirst element selected from the group comprising: about 0.1 to about 4weight percent scandium, about 0.1 to about 20 weight percent erbium,about 0.1 to about 15 weight percent thulium, about 0.1 to about 25weight percent ytterbium, and about 0.1 to about 25 weight percentlutetium; at least one second element selected from the groupcomprising: about 2 to about 30 weight percent gadolinium, about 2 toabout 30 weight percent yttrium, about 0.5 to about 5 weight percentzirconium, about 0.5 to about 10 weight percent titanium, about 0.5 toabout 10 weight percent hafnium, about 0.5 to about 5 weight percentniobium, and about 0.5 to about 15 weight percent iron; and the balancesubstantially aluminum; (b) treating the alloy powder with a rapidsolidification process to form an amorphous phase aluminum alloycomprising about 4 to about 25 weight percent of nickel and about 2 toabout 25 weight percent of cerium; and a coherent L1₂ phase comprising:about 4 to about 25 weight percent of nickel; about 2 to about 25 weightpercent of cerium; at least one first element selected from the groupcomprising: about 0.1 to about 4 weight percent scandium, about 0.1 toabout 20 weight percent erbium, about 0.1 to about 15 weight percentthulium, about 0.1 to 25 weight percent ytterbium, and about 0.1 toabout 25 weight percent lutetium; and at least one second elementselected from the group comprising: about 2 to about 30 weight percentgadolinium, about 2 to about 30 weight percent yttrium, about 0.5 toabout 5 weight percent zirconium, about 0.5 to about 10 weight percenttitanium, about 0.5 to about 10 weight percent hafnium, about 0.5 toabout 5 weight percent niobium, and about 0.5 to about 15 weight percentiron.
 12. The method of claim 11, wherein the rapid solidificationprocess has a cooling rate greater that about 10³° C./second.
 13. Themethod of claim 12, wherein the rapid solidification process comprisesat least one of powder processing, atomization, melt spinning, splatquenching, spray deposition, cold spray, plasma spray, laser melting anddeposition, ball milling and cryomilling.
 14. The method of claim 11,wherein the volume fraction of the amorphous phase ranges from about 50percent to about 95 percent and the volume fraction of the coherent L1₂phase ranges from about 5 percent to about 50 percent.